High Rate of Fecal Carriage of Extended-Spectrum-β-Lactamase Producing Escherichia coli in healthy People in the south of Tehran, IRAN

Introduction and objectives: The incidence of Multi-Drug-Resistant (MDR) Escherichia coli is alarming in the worldwide. E. coli is a main inhabitant of human gut flora. Fecal colonization by Extended-Spectrum-B-Lactamase (ESBL) producing E. coli (EPE) in healthy individuals contributes in their dissemination. The aim of this study was find out the prevalence, phenotypic resistance pattern and molecular detection of blaCTX-M genes of ESBL producing E. coli in feces of healthy people in Tehran. Materials and methods: A total of 200 stool samples were taken from healthy people at ages of 18-35 years from January to July 2018. All red colonies on Chromagar ESBL and Chromagar carba media were selected as EPE and conventional biochemical tests were used to identification of the E. coli. Antimicrobial susceptibility tests in EPE were performed using disc diffusion method for, quinolones, carbapenems and aminoglycosides antibiotics. Presence of ESBL enzymes were confirmed by phenotypic standard methods. Every EPE were screened for blaCTX-M genes (blaCTXM-15 and blaCTX-M14). Results: In present study, 155/200 (77/5%) E. coli isolates were grown on media which ESBL confirmed in 137/200 (88/5%). The blaCTX-M genes were detected in all isolates that high prevalence was related to blaCTX-M15 (119l137; 86/8%). The blaCTX-M14 gene was detected in the 6/137 (4/3%) only. 86/137 (62/7%) isolates were resistance to quinolones also 11/137(8/02) and 12/ 137(8/7%) isolates resistance to carbapenems and aminoglycosides respectively. Conclusions: The current study demonstrates the high rate of fecal carriage of ESBL producing E. coli harboring bla CTX-M-15 in low income region of Tehran. it should aware us to possibility of increase transmission of these MDR isolates in the part of the city with limited access to well medical care, high population density and poor hygiene. To reduce the risk of accession and subsequent transmission of these isolates in healthy people, fecal carriage of high-risk people in community should be the center of attention.

Keywords:

Antibiotic resistant , Intestinal microbiota , Community carriage